1. Field of the Invention
The present invention generally relates to apparatus and methods for making or breaking tubular connections. Particularly, the present invention relates to an apparatus for rotating one tubular relative to another tubular. More particularly, the present invention relates a spinner for rotating a tubular at a high rate of speed during make up/break out of a tubular connection.
2. Description of the Related Art
In the construction of oil or gas wells it is usually necessary to construct long drill pipes. Due to the length of these pipes, sections of pipe are progressively added to the pipe string as it is lowered into the well from a drilling platform. In particular, when it is desired to add a section of pipe, the pipe string is initially restrained from falling into the well by applying the slips of a spider located in the floor of the drilling platform. The new section of pipe is then moved from a rack to the well center above the spider. The threaded pin of the section of pipe to be connected is then located over the threaded box of the pipe string in the well and the connection is made up by rotation therebetween. Thereafter, the newly extended pipe string is released from the spider. The whole pipe string is then lowered until the top of the pipe section is adjacent the spider whereupon the slips of the spider are re-applied to maintain the pipe string in the wellbore.
It is common practice to use a tong assembly to apply a predetermined torque to make up the connection. The tong assembly is typically located on the platform, either on rails, or hung from a derrick on a chain. In order to make up or break out a threaded connection, the tong assembly has a two tong arrangement. An active (or wrenching) tong supplies torque to the section of pipe above the threaded connection, while a passive (or back up) tong supplies a reaction torque below the threaded connection. Particularly, the back up tong clamps the pipe string below the threaded connection, and prevents it from rotating. The clamping of the pipe string may be performed mechanically, hydraulically, or pneumatically. The wrenching tong clamps the upper part of the connection and is driven so that it supplies torque for a limited angle to rotate the section of pipe relative to the pipe string.
This power tong arrangement may also be used to make up connections between other types of wellbore tubulars, for example, casing and tubing.
In order to make up or break out a drill pipe connection, high torque must be supplied over a large angle. This angle is sometimes six times higher than a conventional wrenching tong can supply. In order to overcome this, the wrenching tong must grip and wrench the pipe section repeatedly to fully tighten or break the threaded connection. Due to the high costs associated with the construction of oil and gas wells, time is critical, and the repeated clamping and unclamping of the wrenching tong increases the time needed to attach each new section of tubular.
Spinners have been used in combination with the power tong assembly to facilitate the tubular connection process. Spinners are typically designed to rapidly rotate the pipe section. Spinners generally include rollers for engaging the pipe section about its periphery. The rollers are rotated to spin the pipe section relative to the pipe string to make up the connection.
The ongoing challenge to reduce operational time necessitates a spinner that is capable of handling a wide range of tubular sizes. Because oil rigs have limited space, it would be desirable to have one spinner for handling the different sized tubulars encountered on a rig. Another benefit of using only one spinner is that time required to adjust the spinner, such as changing the size of the rollers, is eliminated.
There is a need, therefore, for an improved apparatus for making or breaking a tubular connection. There is also a need for an apparatus that will reduce the time it takes to make up or break out a tubular connection. There is a further need to quickly adjust to the size of the tubular to be handled. There is also a need for an apparatus capable of working in combination with a tong assembly to make up or break out a tubular connection.